Harderoporphyria: a variant hereditary coproporphyria. Y Nordmann, … , B Cartigny, G Fontaine J Clin Invest. 1983;72(3):1139-1149. https://doi.org/10.1172/JCI111039. Research Article Three siblings with intense jaundice and hemolytic anemia at birth were found to excrete a high level of coproporphyrin in their urine and feces; the pattern of fecal porphyrin excretion was atypical for hereditary coproporphyria because the major porphyrin was harderoporphyrin (greater than 60%; normal value is less than 20%). The lymphocyte coproporphyrinogen III oxidase activity of each patient was 10% of control values, which suggests a homozygous state. Both parents showed only mild abnormalities in porphyrin excretion and lymphocyte coproporphyrinogen III oxidase activity decreased to 50% of normal values, as is expected in heterozygous cases of hereditary coproporphyria. Kinetic parameters of coproporphyrinogen III oxidase from these patients were clearly modified, with a Michaelis constant 15-20- fold higher than normal values when using coproporphyrinogen or harderoporphyrinogen as substrates. Maximal velocity was half the normal value, and we also observed a marked sensitivity to thermal denaturation. The possibility that a mutation affecting the enzyme on the active center which is specifically involved in the second decarboxylation (from harderoporphyrinogen to protoporphyrinogen) was eliminated by experiments on rat liver that showed that coproporphyrinogen and harderoporphyrinogen were metabolized at the same active center. The pattern of porphyrin excretion and the coproporphyrinogen oxidase from the three patients exhibited abnormalities that were different from the abnormalities found in another recently described homozygous case of hereditary coproporphyria. We […] Find the latest version: https://jci.me/111039/pdf Harderoporphyria: A Variant Hereditary Coproporphyria YVES NORDMANN, BERNARD GRANDCHAMP, HUBERT DE VERNEUIL, and LIEM PHUNG, University Paris VII (Faculty of Medicine X. Bichat), Department of Biochemistry, Hospital Louis Mourier, F-92701 Colombes, France BERNARD CARTIGNY and GuY FONTAINE, Centre Hospitalier Regional de Lille, Department of Pediatrics and Medical Genetics, F-59037 Lille, France A B S T R A C T Three siblings with intense jaundice INTRODUCTION and hemolytic anemia at birth were found to excrete Coproporphyrinogen III oxidase (EC 1.3.3.3.) is the a high level of coproporphyrin in their urine and feces; enzyme of the heme pathway that catalyzes the se- the pattern of fecal porphyrin excretion was atypical quential decarboxylation of coproporphyrinogen to for hereditary coproporphyria because the major por- protoporphyrinogen. The reaction is shown in Fig. 1: phyrin was harderoporphyrin (>60%; normal value is 4 of <20%). The lymphocyte coproporphyrinogen III oxi- The propionyl groups in position 2 and copro- dase activity of each patient was 10% of control values, porphyrinogen are decarboxylated and oxidized to which suggests a homozygous state. Both parents yield the two vinyl groups of protoporphyrinogen. Sev- showed only mild abnormalities in porphyrin excretion eral lines of evidence imply that the tricarboxylic in- and lymphocyte coproporphyrinogen III oxidase ac- termediate is harderoporphyrinogen; the propionyl tivity decreased to 50% of normal values, as is expected group on position 2 of coproporphyrinogen is decar- in heterozygous cases of hereditary coproporphyria. boxylated first (1). Kinetic parameters of coproporphyrinogen III oxidase Hereditary coproporphyria (HC)' is a genetic dis- from these patients were clearly modified, with a Mi- order of heme and porphyrin biosynthesis and is in- chaelis constant 15-20-fold higher than normal values herited as an autosomal dominant disorder clinically when using coproporphyrinogen or harderoporphy- resembling two other forms of inherited hepatic por- rinogen as substrates. Maximal velocity was half the phyria, intermittent acute porphyria and porphyria normal value, and we also observed a marked sensi- variegata (2). This disorder is characterized biochem- tivity to thermal denaturation. The possibility that a ically by the excretion of large amounts of copropor- mutation affecting the enzyme on the active center phyrin III, mainly in feces. Data from several inves- which is specifically involved in the second decarbox- tigations (3-5) support the idea that coproporphy- to protoporphy- rinogen III oxidase deficiency (50%) is the primary ylation (from harderoporphyrinogen gene defect in HC. Although it is usually expressed in rinogen) was eliminated by experiments on rat liver the heterozygous state, a case of homozygous HC was that showed that coproporphyrinogen and hardero- recently described (6, 7). The patient in this case was porphyrinogen were metabolized at the same active found to excrete very large amounts of coproporphyrin center. The pattern of porphyrin excretion and the in the urine and feces; lymphocyte coproporphyrino- coproporphyrinogen oxidase from the three patients gen III oxidase activity was only 2% of the control exhibited abnormalities that were different from the level. abnormalities found in another recently described ho- This paper describes a previously unreported variant mozygous case of hereditary coproporphyria. We sug- is characterized the accumulation gest naming this variant of coproporphyrinogen oxi- of porphyria that by dase defect "harderoporphyria." of harderoporphyrin in feces of homozygous patients. ' Abbreviations used in this paper: ALA, 5-aminolevulinic Received for publication 1 December 1982 and in revised acid; HC, hereditary coproporphyria; HPLC, high pressure form 11 May 1983. liquid chromatography. J. Clin. Invest. ©D The American Society for Clinical Investigation, Inc. * 0021-9738/83/09/1139/11 $1.00 1139 Volume 72 September 1983 1139-1149 COPROPORPHYRINOGEN HARDEROPORPHYRINOGEN PROTOPORPHYRINOCEN FIGURE 1 Biosynthesis of protoporphyrinogen from coproporphyrinogen III. This stepwise reaction is catalyzed by coproporphyrinogen oxidase. Harderoporphyrinogen is the natural intermediate between copro- and protoporphyrinogen. Isoharderoporphyrinogen (vinyl group on pyrrole B instead of pyrrole A) has not been isolated from tissues synthesizing protoporphyrin IX; however, isoharderoporphyrinogen is a known substrate of coproporphyrinogen oxidase (17). Me, methyl (-CH3); Pr, propionyl (-CH2-CH2-COOH); V, vinyl (-CH=CH2). The molecular basis of this disease is shown to be a S.M., at the Department of Pediatrics of Lille Hospital when he developed an intense jaundice shortly after his birth. The mutation leading to the presence (at least in lympho- perinatal history revealed normal pregnancy and delivery. cytes) of a coproporphyrinogen III oxidase with mod- Physical findings in addition to jaundice included hepato- ified kinetic properties; this indicates a structural ab- splenomegaly. The total serum bilirubin level was 16.7 mg/ normality of the enzyme which is distinct from a case dl with an unconjugated bilirubin value of 12.1 mg/dl. The previously described. blood group of the baby was the same as that of the mother (O Rh negative). Hematologic data are shown on Table I; the erythrocyte morphology was normal. Exchange trans- METHODS fusion was immediately performed and followed by pho- Case reports. The patients are three siblings born in 1973, totherapy. Soon afterwards, the baby showed a rash with 1975, and 1980 from healthy, nonconsanguineous French vesicles and blisters and a diagnosis of pemphigus was con- parents. Porphyria was first discovered in the second child, sidered. A second rash appeared a few days later when the TABLE I Representative Hematologic Values of the Patients and Their Parents Patients Date RBC Hb Retics Ht Platelets X lo/sll gIl/O ml % X 1031/p S.M. 25 August 1975° 4.0 12.4 10.0 38 83 25 November 1975 2.7 6 15 25 - 10 July 1977 3.7 9.1 3.5 31 396 1 February 1978 4.3 8.5 2.6 31 350 D.M. 11 October 1973' 4.3 10.8 12 40 82 2 November 1973 3.0 8.0 25 24 - 10 July 1977 4.0 9.2 5 30 230 A.M. 13 October 1980° 5.1 12.0 10.0 43 85 22 October 1980 4.00 8.8 16.0 30 - 28 September 1981 3.85 9.7 5.5 32 600 Parents Mother 2 March 1983 4.50 13.4 1.0 41.0 486 Father 2 March 1983 4.88 14.7 1.2 46.5 311 Abbreviations used in this table: RBC, erythrocytes; Retics, reticulocytes; Ht, hematocrit; Hb, hemoglobin. e Date of birth. 1140 Nordmann, Grandchamp, de Verneuil, Phung, Cartigny, and Fontaine primary blisters were not yet completely healed. At this time, tracts obtained by solvent extraction were adjusted to pH a red discoloration of the urine was observed, and the di- 3-4 and extracted in ethylacetate-acetic acid (3:1, vol/vol). agnosis of inherited porphyria was confirmed by the high The mixture was evaporated under reduced pressure at 45°C levels of uro- and coproporphyrin found in the urine (Table and porphyrins were treated overnight with 50 ml of meth- II). No further biological investigation was done in 1975 on anol-sulfuric acid (95:5, vol/vol). Porphyrin esters were ex- this child. tracted into chloroform as previously described (15) and an The elder brother, D.M., had presented similar symptoms aliquot was then injected into a Perkin-Elmer high pressure on the day of his birth. However, like his younger brother, liquid chromatograph (model 604, Perkin-Elmer Corp., Nor- he was sent home with the diagnosis of hemolytic anemia; walk, CT). The column used was a 30 X 0.4 cm (10 Arm) the cause remains unknown at this time. During the next Porasil (Waters Instruments, Inc., Rochester, MN). The chro- two years, his hepatosplenomegaly disappeared and a com- matogram was recorded at 404 nm using an LC 55 Perkin- pensating hemolytic process persisted. His growth and de- Elmer detector. Peak areas were determined with a com- velopment remained normal; neither abnormal cutaneous puting integrator (icap 5, LTT, Paris, France). Analysis was features nor red discolorations of the urine or teeth were carried out successively in two different solvent systems at noticed. However, in 1975, when urine porphyrins were a flow rate of 1.5 ml/mn. The first one (ethylacetate/cyclo- studied, a very high level of coproporphyrin was found hexane, 55:45, vol/vol) separated porphyrin esters with 2 to (Table II).